Rubber reclaiming apparatus



Sept. 4, 1962 Filed July 11, 1960 FIG.|

2 Sheets-Sheet 1 INVENTOR. 5455227 /.V/%reao v Sept. 4, 1962 c. H.PETERSON 3,051,990

RUBBER RECLAIMING APPARATUS Filed July 11, 1960 2 Sheets-Sheet 2 FIG.2

I N VEN TOR. 62-15752 1% /%/21JOM "WW/M4 MM 3,951,990 Patented Sept. 4,1962 free 3,051,996 RUBBER RECLAIMHNG APPARATUS Chester H. Peterson,Eggertsvilie, N.Y., assignor to US. Rubber Reclaiming Co., Inc.,Cheektowaga, N.Y., a corporation of New York Filed July 11, 1960, Ser.No. 42,036 8 Claims. (Cl. 1814) This invention relates to apparatus forthe continuous reclaiming of rubber (i.e. vulcanized conjugated dienepolymers, and the like), and more particularly to im provements in themeans for conducting the reclaimed rubber away from the means whereby itis reclaimed while being propelled forwardly.

It has been found that an improved product is provided if successiverefining actions between moving and stationary surfaces are carried outduring the movement of the reclaim forwardly from the propulsive means.In addition, it has been found that a high uniformity of the product canbe secured when such movement is conducted in a straight line from thepropulsive means to the final extrusion orifice, so that the variousportions of the reclaim will be subjected to similar conditions duringits forward movement.

1 It is also of importance that the reclaim be subjected to a coolingaction between successive refining steps.

With the foregoing and other considerations in view, the presentinvention contemplates the provision of forwardly disposed means securedto and rotating on the same axis as a reclaiming screw and ofcooperating stationary means serving as a forward continuation of thereclaiming casing in which such a screw operates whereby there areprovided successive annular restricted refining channels separated by awider annular channel.

In various of' its more specific aspects, the invention contemplates theprovision of cooling means at said wider annular channel, the provisionof particularly shaped channels, the provision of means for readilyadjusting the size of the final annular channel, the provision of meansfor conducting the reclaim beyond the orifice of the final channel, andother features of construction as will more particularly appearhereinafter.

By means of the present invention there is provided an additionaldegreeof working whereby a supplemental refining action is obtained andtendencies for unplasticized particles to leave the machine areminimized.

The invention accordingly comprises the features of construction,combinations of elements, and arrangement of parts, which will beexemplified in the constructions hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal section view of one form of apparatusembodying the invention;

FIG. 2 is a transverse sectional view along the lines 22 of FIG. 1; and

FIG. 3 is an exploded view showing certain of the parts.

In the illustrated embodiment of the invention, there is provided anelongated hollow cylindrical casing in which rubber, delivered incomminuted form to the rearward end thereof, as from a suitable hopper(not shown), may be reclaimed as it is worked and propelled forwardlytherethru by a screw 12 which is rotated by a suitable source of powersuch as an electric motor (not shown). The screw 12, in the presentinstance, is formed with a series of sets of propelling thread portions14 and working thread portions 15, projecting only slightly from a thickstem 16, as, for example, set forth in United States Patent 2,653,348.The screw in the present instance may be 12 inches in diameter.

From the forward end of the casing 10 and providing therewith acontinuous interior wall 17 is a casing por tion 18 the diameter ofwhich decreases gradually in a forward direction, and forwardly of thisis a similar casing portion 28 providing a further continuing interiorwall 21 which slopes inwardly more sharply, and a still furthercontinuing wall 22 which slopes outwardly.

The forward end of the screw 12 is provided with a threaded bore 24 inwhich is tightly screwed to rotate with the screw 12 a rearwardprojection 25 from a cone 26 having an outer forwardly interior slopingwall 27 arranged to provide a restricted annular channel 28 between itand the wall 17, the walls 17 and 27 being substantially uniformlyspaced throughout their longitudinal extent. At the rear end of therotating cone 26 a wall 30 which slopes outwardly from the stem 16 isprovided. Cooling passageways 31 are provided in the housing whichsurrounds the rotating cone 26.

Forwardly of the wall 27 is a cone portion 32 having an outer wall 33which slopes inwardly more sharply than the wall 21. threaded bore 34 inwhich a threaded projection 35 on a mandrel 36 is tightly screwed. Onthe outer cylindrical surface 40 of the mandrel 36 there is tightly butslidably fitted a rotating inverted conical die 42, the rearward slidingmovement of which is limited by cooperating shoulders 43 and 44 on themandrel and the die 42 respectively. The fit of the die 42 on themandrel is tight enough to assure the rotation of the die with themandrel. A key 45 and keyway 46 may be provided, if desired, so as toassure more positively the rotation of the die 42 with the mandrel 36and the screw 12. The mandrel is provided with a threaded forwardprojection 48 on which there is screwed a nut 49 which may be screwed infully (to the position shown) to hold the end piece in a rearwardposition shown or only partially to permit the pressure of the rubberthereon to hold the rotating die 42 more or less forwardly as desired.

The outer wall 52 of the rotating die 42 has a slope corresponding tothe wall 22 and provides a channel 54' therebetween. When the shoulders43 and 44 are in contact, the channel 54 is much more restricted thanthechannel 28, but the effective size of the channel 54 may be increasedby the adjustment of the nut 49 when desired, tho ordinarily not so muchas to reduce the resistance to flow or the back pressure in chamber tosuch a degree that voids would form or be capable of forming.

The wall 52 extends rearwardly of the wall 22, inside the wall 21, sothat a wide channel or plenum chamber 60 is provided between thechannels 28 and 54; and outside the casing portion 20 there is provideda chamber 62 thru which a cooling fluid may be flowed. The plenumchamber 60 serves to smooth out the flow of material and to absorbpressure surges. It serves further to provide a degree of cooling afterthe intensive shearing action on and consequent heat building up in thematerial.

Rubber worked, propelled, and reclaimed within the casing 10 flows thruthe channel 28 where it is refined by the rotation of the cone 26 withrespect to the stationary wall 27, thru the chamber 60 where it is,preferably, compacted and cooled, and out thru the channel 54 where itis further refined.

In order to remove the hot reclaimed rubber forwardly away from thechannel 54 and beyond the casing portion 20, so as to avoid thepossibility of hot rubber adhering to an irregular surface such as thatof the nut 49, there is mounted on the forward end of the rotating die42 a polished hollow cylindrical member 65 of the same outer diameter asthe forward end of the die 42 and on This cone portion 32 is formed witha which the rubber slides easily without adhering, this member beingheld in place by an annular cross-piece 66 which is integral therewithand which fits between the nut 49, and a lock nut 67 which is screwed onthe outer end of the mandrel 36. The nut 67 and the member 65 may beremoved to permit the adjustment of the nut 49.

By the use of a construction such as exemplified, excellent control offlow is obtained thru more efficient cooling and simple adjustments ofclearances. The result of the tandem operation of the rotating cone,plenum chamber, and rotating die is to provide a smooth, uniform flow atdesirably low exit temperatures. External cooling without excessivesmoking is certain and effective. Fume and smoke control are positiveand effective. Points of hold-up, i.e. dead spots, in which materialcould cure up and present difliculties in the finishing operation, areeliminated. Maintenance and initial cost are low. Because of the steadyflow and the rotation of the die, die wear is not critical since it isuniformly concentric around the circumference. This results in moreuniform clearance adjustment as wear progresses. A high degree ofproduction is obtained, shut-down and start-up times are short, andgreat simplicity of construction is attained.

Since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

The invention claimed is:

1. Rubber reclaiming apparatus comprising a stationary outer wallproviding a cylindrical reclaiming chamber, a screw rotatable withinsaid chamber for moving rubber forwardly thru said chamber to reclaimit, means providing an annular passageway beyond the discharge end ofsaid screw and comprising stationary outer wall means and an interiorwall means secured to said screw and rotating therewith and providingwith said outer wall a rearward restricted annular channel and a forwardrestricted annular channel, and providing also between said rearwardrestricted channel and said forward restricted channel a wider annularchamber which is less restrictive than either of said channels and theinterior wall of which rotates with said screw and the exterior wall ofwhich is stationary, said forward restricted channel being morerestrictive than said rearward restricted channel.

2. Apparatus as in claim 1 wherein cooling means is provided exteriorlyof said wider annular chamber.

3. Apparatus as in claim 1 wherein said outer wall is of less interiordiameter at said forward channel than at said rearward channel.

4. Apparatus as in claim 1 wherein said wall means decrease in diameteralong said rearward annular channel and increase in diameter along saidforward annular channel.

5. Apparatus as in claim 4 wherein the forward portion of said interiorwall means is adjustably mounted to vary the size of said forwardannular channel.

6. Apparatus as in claim 1 wherein there is provided, at the forward endof said interior wall means, means extending forwardly beyond said outerwall means to guide the reclaimed rubber beyond the forward end of thelatter.

7. Apparatus as in claim 6 wherein said forwardlyextending means isremovably mounted.

8. Rubber reclaiming apparatus comprising a stationary hollowcylindrical casing, rotatable screw means therein for reclaiming rubberand moving it forwardly the'rethru, a gradually-decreasing-diameterconical element mounted on the forward end of said screw means androtating therewith, stationary wall means serving as a continuation ofsaid casing and defining a restricted annular channel between it andsaid conical element, a reduced-diameter element extending forwardlyfrom said conical element and rotating therewith, further exteriorstationary wall means forming an annular chamber outside said rotatingreduced-diameter element, a shaft threaded into said reduced-diameterelement and rotating therewith, an increasing-diameter conical elementfitted on said shaft for rotation therewith, and further stationary wallmeans defining a restricted annular channel about the last-mentionedconical element said annular chamber being less restrictive than thefirst-mentioned annular channel and the second-mentioned annular channelbeing more restrictive than the first-mentioned annular channel.

References Cited in the file of this patent UNITED STATES PATENTS454,030 Clark June 16, 1891 1,159,895 Canda Nov. 9, 1915 2,461,630 CozzoFeb. 15, 1949 2,514,841 Chase July 11, 1950 2,747,223 Cady May 29, 19562,979,768 Nichols Apr. 18, 196-1 FOREIGN PATENTS 961,211 Germany a Apr.4, 1957

